lour
See
An Asiatic sardine (
To be dark, gloomy, and threatening, as clouds; to be covered with dark and threatening clouds, as the sky; to show threatening signs of approach, as a tempest.
verbTo frown; to look sullen.
verblook angry or sullen, wrinkle one’s forehead, as if to signal disapproval
verbmake lower or quieter
verbset lower